Pope Francis hits the streets, getting a rock- star-style greeting — and stunning his security detail — after holding his first Sunday Mass as pontiff yesterday.

The pope, who will be officially installed tomorrow, grabbed hands outside the Vatican’s tiny parish church, St. Anna’s, before delivering an off-the-cuff speech about forgiveness to a crowd of 300,000 in St. Peter’s Square.

He earlier shocked the faithful by appearing at a Vatican side gate, where he shook hands, kissed babies and told jokes.

It was all a startling break from tradition — because pontiffs rarely leave the security of the bulletproof Popemobile while in a crowd.

Francis delivered his speech from the window of the papal residence — and signed off, “Buon pranzo,” or “Have a good lunch.”